compiler: mark stringFromRunes as nocapture/readonly

tinygo-org · Oct 19, 2024 · 951e50c · 951e50c
1 parent 40c9c66
commit 951e50c
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Showing 2 changed files with 7 additions and 0 deletions.
diff --git a/compiler/symbol.go b/compiler/symbol.go
@@ -175,6 +175,9 @@ func (c *compilerContext) getFunction(fn *ssa.Function) (llvm.Type, llvm.Value)
 	case "runtime.stringFromBytes":
 		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
+	case "runtime.stringFromRunes":
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
 	case "runtime.trackPointer":
 		// This function is necessary for tracking pointers on the stack in a
 		// portable way (see gc_stack_portable.go). Indicate to the optimizer

diff --git a/transform/testdata/allocs2.go b/transform/testdata/allocs2.go
@@ -54,6 +54,10 @@ func main() {
 	var buf [32]byte
 	s := string(buf[:])
 	println(len(s))
+
+	var rbuf [5]rune
+	s = string(rbuf[:])
+	println(s)
 }
 
 func derefInt(x *int) int {